The category correction
"Next.js vs React" is not a versus. Next.js is React plus a meta-framework — routing, server rendering conventions, data-fetching opinions, deployment shape. The actual choice: plain React (Vite-era SPA) or React-with-an-operating-system.
Plain React (Vite) when
The app lives behind a login and has no SEO surface: dashboards, internal tools, portals, SaaS app shells. SPAs are simpler to reason about, cheaper to host, faster to iterate, and Vite's developer experience is superb. SEO is solvable-but-annoying if it ever matters; if it will never matter, do not pay the meta-framework tax.
Next.js when
Any public-facing surface where load-speed-and-indexing matter: marketing pages, ecommerce, content products. Server rendering stops being optional polish and becomes the product requirement. Next also brings routing and deployment conventions that spare a growing team a hundred small decisions — App Router opinions included, like them or not.
The costs nobody puts on the card
Next.js: framework velocity (major-version churn is real; budget maintenance), deployment coupling (Vercel-shaped defaults travel poorly to some infra), and conceptual load — server components blur boundaries juniors were only just learning. Plain React: you own routing, data caching, SSR-if-ever-needed decisions yourself — the freedom is billed in architecture hours.
Translation for your project
Public product → Next.js, accept the maintenance. Private product → plain React + Vite, bank the simplicity. Mixed product (app + public site) → split them: static site for the surface, SPA for the app — a seam that outlives every framework release cycle.
Both are delivered here — Next.js and React — the recommendation follows the product's surface, not a preference.